Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease characterized by chronically poor airflow. It typically worsens over time. The main symptoms include shortness of breath, cough, and sputum production. Most people with chronic bronchitis have COPD.

Tobacco smoking is the most common cause of COPD, with a number of other factors such as air pollution and genetics playing a smaller role. In the developing world, another common source of air pollution is poorly vented cooking and heating fires.

COPD can be prevented by reducing exposure to known environmental risk factors. This includes efforts to decrease rates of smoking and to improve indoor and outdoor air quality. COPD treatments include stopping smoking, vaccinations, rehabilitation, and often taking inhaled bronchodilators and steroids. Some people may benefit from long-term oxygen therapy or lung transplants. In those who have periods of acute worsening, increased use of medications and hospitalization may be needed.

Worldwide, COPD affects 329 million people or nearly 5% of the population. In 2013, it resulted in 2.9 million deaths up from 2.4 million deaths in 1990. The number of deaths is projected to increase due to higher smoking rates and an aging population in many countries.